Once a commercial product then made free for a time then website just disappear... Don't think it comes back on the wayback either... Interesting GUI & concept, pretty easy to get on with & apparently has option to 'ACiDize' your exports... Fun stuff from yesteryear should run on any old OS... Copy the freeware code before launch this is an open directory so no install required run from any location...
https://archive.org/details/sequ-beat-pro-7
https://archive.org/details/sequ-beat-pro-7